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Radon Levels in Iredell County, North Carolina

EPA puts Iredell County in Zone 2, its middle radon zone, and only 4 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    21.8%

    0.8 pts below NC

    Iredell
    21.8%
    NC
    22.6%

    1,146 tests, 2008 to 2017

  • Median result

    1.8pCi/L

    Below action level

    Iredell
    1.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    1,146

    14th of 75 by tests

    Iredell
    1,146
    Wake
    9,694

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in NC

    36 of 75

    Middle half

    Iredell
    21.8%
    Transylvania
    47.8%

    By share, of 75 with 30+ tests

Read a result for Iredell County

Starts at Iredell County's median, 1.8 pCi/L

1.8pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 1.8 pCi/L

Below 2 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Iredell County's median reported result, 2008 to 2017.

Interpret this reading

The data

Iredell County, At a glance

Iredell County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Iredell County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 68% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Iredell County, 2022

Share of reported tests at or above 4 pCi/L, by year, Iredell County
Share of reported tests at or above 4 pCi/L, by year, Iredell County
YearShare of reported tests at or above 4 pCi/L
201421.3%
202018.0%
202113.8%
202250.0%

2022: 50.0%. Across these years the share ran from 13.8% to 50.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 4 tests were reported to CDC for Iredell County over 2022, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).

How to read these figures

Iredell County, Compared

Iredell County radon figures, compared

Calculated by Radon411

Iredell County's 1,146 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.8 pCi/L and a maximum of 29.7 pCi/L, and 21.8% reached 4 pCi/L. North Carolina as a whole (99 North Carolina counties, pooled) comes to 22.6%: 0.8 points higher than here.

The newest figure, in 2022, counts only 4 tests (50.0% at or above 4 pCi/L), too few to compare, so this reading uses the 1,146-test figure.

Among its state's counties it ranks 36th of 75 North Carolina counties with 30 or more tests for the same period. Statewide for the same period, Transylvania County reported the highest share (47.8%) and Nash County the lowest (0.0%).

Below the action level, 615 tests (53.7%) came in under 2 pCi/L, against 55.6% statewide, and 281 tests (24.5%) fell between 2 and 4, against 21.8% statewide. The busiest year on file was 2020, with 283 tests reported; the quietest, 2022, had 4.

EPA's 1993 zone map puts Iredell County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 68% of the county's land moderate radon potential.

Next door, the shares run from 8.5% in Mecklenburg County to 44.3% in Wilkes County, with Rowan County, Davie County and Cabarrus County below Iredell County. Over 3 years of annual figures the share fell 7.5 points, from 21.3% in 2014 to 13.8% in 2021; its peak was 21.3% in 2014.

CDC also counts 105 tests taken after mitigation in Iredell County for the same period: tests in homes where a fix was already in.

Share of reported tests at or above 4 pCi/L by year, Iredell County against North Carolina2014 to 2021, years with 30 or more tests: Iredell County 21.3% to 13.8%, the state's pooled share 14.9% in 2021.
Iredell CountyNorth Carolina, pooled
Share of reported tests at or above 4 pCi/L by year, Iredell County against North Carolina: data table
YearTestsIredell County, at or above 4 pCi/LNorth Carolina, pooled
201417821.3%21.9%
202028318.0%21.1%
20218713.8%14.9%
Iredell County against North Carolina, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Iredell County
Iredell County1,14621.8%1.8 pCi/LThis county
North Carolina, pooled99 counties, pooled73,13922.6%Not pooled+0.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+13.9 points
Transylvania Countyhighest in the state3,86247.8%3.7 pCi/L+26.0 points
Nash Countylowest in the state300.0%0.2 pCi/L−21.8 points
Wilkes County, NCborders it40244.3%3.5 pCi/L+22.5 points
Alexander County, NCborders it31132.8%2.5 pCi/L+11.0 points
Lincoln County, NCborders it70829.0%2.4 pCi/L+7.2 points
Yadkin County, NCborders it19928.6%2.2 pCi/L+6.8 points
Catawba County, NCborders it1,25924.8%2.0 pCi/L+3.0 points
Rowan County, NCborders it62617.7%1.4 pCi/L−4.1 points
Davie County, NCborders it69417.4%1.7 pCi/L−4.4 points
Cabarrus County, NCborders it8808.8%1.0 pCi/L−13.0 points
Mecklenburg County, NCborders it3,7538.5%0.9 pCi/L−13.3 points
Where Iredell County's reported results fell, 2008 to 2017, laboratory, beside North Carolina and the United States
ResultIredell County testsIredell County shareNorth Carolina shareU.S. shareAgainst North Carolina
Under 2 pCi/L61553.7%55.6%39.6%−1.9 points
2 to 4 pCi/L28124.5%21.8%24.7%+2.7 points
4 pCi/L and above25021.8%22.6%35.7%−0.8 points
Iredell County ranked among the 75 North Carolina counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Dare County31 of 754126.8%0.1 pCi/L
Rutherford County32 of 7551125.6%2.4 pCi/L
Davidson County33 of 751,26525.5%1.8 pCi/L
Stanly County34 of 7522925.3%2.2 pCi/L
Catawba County35 of 751,25924.8%2.0 pCi/L
Iredell County36 of 751,14621.8%1.8 pCi/L
Stokes County37 of 7559221.6%1.8 pCi/L
Montgomery County38 of 7510320.4%1.5 pCi/L
Moore County39 of 759919.2%1.3 pCi/L
Franklin County40 of 7520419.1%1.4 pCi/L
Gaston County41 of 7559319.1%1.5 pCi/L
Iredell County radon tests by year, against North Carolina's pooled share
YearTestsAt or above 4 pCi/LMedianHighestNorth Carolina, pooledChange from the row before
2022450.0%3.0 pCi/L7.0 pCi/L10.7%+36.2 points
20218713.8%1.0 pCi/L14.0 pCi/L14.9%−4.2 points
202028318.0%1.1 pCi/L94.3 pCi/L21.1%−3.3 points
201417821.3%1.0 pCi/L19.5 pCi/L21.9%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Iredell County, Geology

The ground under Iredell County

Predicted

USGS's geologic map splits Iredell County: 67.6% of its land is moderate radon potential and 32.4% low. The map puts 63.1% of Iredell County in the area it calls Inner Piedmont Belt and 32.4% in Charlotte Belt, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).

USGS's geologic areas under Iredell County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Inner Piedmont BeltProterozoic through Cambrian biotite gneiss and schist, and mica schist.Moderate1163.1%
Charlotte BeltIgneous rocks, including granite, gabbro, and diorite.Low832.4%
Kings Mountain BeltProterozoic-Cambrain metasedimentary and metavolcanic rocks.Moderate114.5%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Iredell County beside the ground around it

Across North Carolina 1.3% of the land is rated high; none of Iredell County's is. Of the 9 counties that border it, 5 have more moderate-potential ground, Alexander County the most at 100%.

Share of land by USGS radon potential: Iredell County, the 9 counties bordering it and North Carolina
AreaEPA zoneLow potentialModerate potentialHigh potential
Iredell CountyZone 232.4%67.6%None
Catawba CountyZone 22.6%97.4%None
Alexander CountyZone 2None100%None
Rowan CountyZone 3100%NoneNone
Davie CountyZone 392.3%7.7%None
Lincoln CountyZone 217.0%83.0%None
Yadkin CountyZone 23.2%96.8%None
Wilkes CountyZone 2None100%None
Mecklenburg CountyZone 3100%NoneNone
Cabarrus CountyZone 3100%NoneNone
North Carolina100 counties, pooled by land areaVaries64.8%33.0%1.3%

The map rates the ground, not the air in any home.

Local help

Iredell County, Local resources

Radon testing and mitigation in Iredell County

What North Carolina's program says
Licensing of radon professionals
The North Carolina Radon Program is presently developing a Radon Proficiency Program as directed by Session Law 2023-91 House Bill 782 .

What it means

Iredell County, Questions

Questions about radon in Iredell County

Are radon levels high in Iredell County?

In 2022, 50.0% of the radon tests reported to CDC for Iredell County, North Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of 75 North Carolina counties with 30 or more tests for the same period, 35 reported a higher share; pooled, the state comes to 22.6%.

Which counties border Iredell County?

Iredell County borders 9 counties: Catawba County, Alexander County, Rowan County, Davie County, Lincoln County, Yadkin County, Wilkes County, Mecklenburg County and Cabarrus County.

Products

Iredell County, Products

Testing a home in Iredell County

In Iredell County, 21.8% of 1,146 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.6% pooled across North Carolina. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Iredell County; a long-term test tells the year-round average.

Test kits and monitors3

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Best radon monitors for Iredell County homes, compared

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Iredell County, Bordering counties

Counties bordering Iredell County

Calculated by Radon411

Iredell County, Cities and towns

Cities and towns in Iredell County

Iredell County is growing: the Census Bureau puts it at 211,798 residents on July 1, 2025, up 12.9% from 187,676 in 2020. That works out to 369 people per square mile of land. Its largest town, Mooresville, has 55,842 residents, 26.4% of the total. CDC's 1,146 reported tests for 2008 to 2017 work out to 5.4 per 1,000 residents (2025 estimate), close to North Carolina's 6.5.

From Mooresville to Love Valley, CDC publishes no figure by town: each reads Iredell County's.

The cities and towns in Iredell County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Mooresville55,842+10.5%26.4%
Statesville32,181+12.4%15.2%
Davidsonextends beyond Iredell County16,662+11.9%Counted whole
Troutman4,336+13.2%2.0%
Harmony619+14.0%0.3%
Love Valley183+14.4%Under 0.1%

6 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Iredell County is counted whole, so it has no share.

Iredell County, Homes

Homes in Iredell County

Of Iredell County's 81,785 homes, 71% are detached houses, against 65% across North Carolina; 12% are mobile homes. Half of its homes were built before 1996, close to North Carolina's 1990: 12% date from before 1960 and 42% from 2000 or later. 71% of occupied homes are lived in by their owner (North Carolina: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Iredell County, North Carolina, 2019 to 2023
HomesIredell CountyNorth Carolina
Housing units81,7854,815,195
Detached houses71%65%
In buildings of 5 or more10%14%
Mobile homes12%11%
Built before 196012%14%
Built since 200042%33%
Middle year built19961990
Owner-occupied71%66%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.